Process of brazing sheet-metal packages.



No. 685,975. Patented Nov.'5, 190i.

J. c. HAMMER-8L, A. A. ,cowuas. PROCESS OF BRAZING SHEET METAL PAGKAGES.

(Application filed Feb. 11, 1901.) (No Model.) 2 Sheefs-Sheet WITNESSESagwgzig J By W Attorneys.

No. 685,975. Patented NOV. 5, I99]. J. C. DANZIGER G. A. A. CQWLES.PROCESS OF BBAZING SHEET METAL PACKAGES.

' (Application filed Feb. 1 1, 190.1)

2 Sheets$heat 2.

(No Model.

WITNESSES Q V gVEIYTORS Attorneys.

w: NORRIS PETKRS be, Pnbmumcq wAsumo'rcn. n. c.

NITED STATES PATENT OFFicE.

JACOB o. DAnzIenR AND ARTHUR A. COWLES, OF DETROIT, MlCIIIGAN.

PROCESS OF BRAZING SHEET-METAL PACKAGES.

SPECIFICATION forming part of Letters Patent N 0. 685,975, datedNovember 5, 1901. Application filed February 11, 1901. Serial No.46,856. (No model.)

To all whom it may concern;

Be it known that we, JACOB O. DANZIGER and ARTHURA.COWLES,citizens oftheUnited States, residing at Detroit, county of Vayne, State of Michigan,have invented a certain new and useful Improvement in Processes ofBrazing Sheet-Metal Packages; and we do declare the following to be afull, clear, and exact description of the invention, such as will enableothers skilled in the art to which it pertains to make and use the same,reference being had to the accompanying drawings, which form a part ofthis specification.

.Ourinvention relates to the method of man ufacturing metal packagesmade of sheet iron or steel; and it consists in the process ofmanipulating and brazing the parts together, substantially ashereinafter specified and claimed. Heretofore packages of this charactermade of sheet steel or iron hadtheir heads or ends attached to the bodyof the package by either riveting, like that shown in patent to Grant,No. 557,504, dated March 31, 1896, and afterward soldering by commonsolder, or by cleaning and tinning the surfaces, then riveting them andbrazing by the ordinary process of brazing then known. In order tosuccessfully braze a package of this character, the method of brazingmust be adapted to meet certain conditions. that brazing cannot beordinarily successfully performed unless the surfaces are cleaned and inperfect contact, and also that they be kept in contact during theprocess of brazing. It is also well known that brazing requires not onlya high degree of heat to melt the brazing material, but that the platesto be brazed must also be raised to substantially the same or greaterdegrees of temperature. It is further well known that this cannot bedone with plates or sheets of steel or iron, especially of anythickness, without raising a scale on the surfaces and also warping theplates to a greater or less degree, and that the warping during bothheating and cooling will tend to prevent the retention of that closeconnection between the surfaces which is essential to brazing. Further,it is also well known that during the solidification of brazing materialthere is a point of critical tempcrature at which the material isextremely It is well known ter described, consisting usually of barrelsor analogous structures, are very difficult to handle and at the sametime meet all of the conditions necessary to securing the perfect jointrequisite in order to make them liquid and gas tight. By the methodhereinafter described we have met all these conditions and are enabledto successfully braze large packages of from fifty gallons capacityupward with rapidity and success.

In the drawings, Figure l is a sectional elevation of the apparatus usedand of a cylindrical package during the process of brazing in the headthereof. Fig. 2 is a plan View of the furnace employed. Fig. 3 shows thepreferred method of assembling the parts to be brazed, portions beingbroken away. Fig. 4. is an enlarged sectional drawing of Fig. 3. Fig. 5is a detail of the rollers, &c., shown in Fig. 1.

In thedrawings, A represents the furnace which we employ, whichconsists, essentially, of a pit or depression shaped to admit of thereception of the article to be operated upon, as shown in Fig. 1,consisting, essentially, of

a depression B. The material of which the walls of the depression isformed may be fireclay or any substance which is adapted to resist ahigh temperature. Two twyers G D project from each of these depressions,respectively. These twyers are connected to a source of gas-supply,which may be controlled by valves E F, so that the amount of heatdelivered by each can be modified to suit conditions. i

The apparatus for furnishing gas and air are not novel and form no partof ourinvention, except that they must be so arranged that a high degreeof temperature canbe attained and that the respective temperatures ofeach may be controllable.

G is a package orbarrel the chime of which is located in the curveddepression of the furnace and practically directly between the twyers, 9being the head of the package and g being the cylindrical portion. Asshown in the drawings, the head is united to the shell by being pressedinto a cup form, as shown by the flanges at g 9 and adapted to beinserted into the end of the shell somewhat farther than the depth ofthe cup and until it meets the annular groove gfiwhich groove is,pressed into the shell. The cup-head is so formed as to form a closecontact with the shell at all portions or substantially all portions ofits outer surface. While in this position the lip of the shell at g maybe turned over to embrace the edge of the cup-formed head, or it mightbe held by riveting, if desired. The opposite end of the package, if notalready brazed in, is open, oran opening is usuallyleft therein for theinsertion of a bung or valve, and in this condition,either with the openhead or with the opening uppermost, it is placed so that the chime to beoperated upon is, as already stated, within the depression of thefurnace. YVhile in this position the package is supported and held incondition to rotate by means of two traveling wheels II H, mounted upona frame J, the chime opposite the portion located between the twyersbeing held also by a grooved roller K. It is obvious that while in thisposition and supported by these rollers J J and K the package can berotated. When placed in position, the gas-jets are turned on and lightedand that portion of the flange or chime and a portion of the material ofthe shell and head adjacent thereto becomes highly heated. This heatingcauses both to expand, and if the circumferential shell was heated tohigher temperature than the head adjacent thereto, which might veryreadily happen, its tendency would be to spring away from the head byswelling up therefrom. The temperature therefore of each jet must be soadjusted that if anything the head is made hotter than the shell whichkeeps the two surfaces in close contact. After being heated to someextent and before finally heating it to the desired temperature therequisite amount of fluxing material is fed in through the top oropening, which melts and penetrates between the surfaces and unites withthe scale, forming a glass, which remains in the bottom of thedepression on the interior of the package, as shown at L L. Brazingmaterial is then also fed in in small quantities as granules or bitsofiron and its specific gravity being heavier than that of the fluxin gmaterial falls into the angle between the head and shell at M and melts.Its specific gravity compels it to take the place of the fluxingmaterial between the plates. It descends therefore and passes throughand fills up'all of the spaces which may exist between the plates,uniting the surfaces. As soon as it has acquired the requisite degree oftemperature to melt the package is rotated just fast enough to permitthe wave of heat created by the gas-jets to slowly advance around theperiphery of the chime without any substantial cooling in thetranslation of the surfaces.

,It is obvious that as the package is slowly rotated the fiuxingmaterial will precede the brazing material in consequence of its beinghigher and in connection with the curvature of the angle due to theposition of the package. This is illustrated at N. It thereforepenetrates between the shell and head, cleans the surfaces of the sheetsin contact, and prepares them for the action of the brazing materialwhich follows as the angle is slowly depressed during the revolution. Asthe brazing portion successively rises it is again subjected to thefluxing material, as shown at P, and gradually cools as it is movedslowly away from the influence of the gas-jets. By arranging the packagein this manner and subjecting portions of it successively and slowly tothe required temperature while feeding the fluxing material and brazingmaterial in gradually in the manner specified enables the brazing to bedone and the plates to gradually cool without any degree of warpingwhich shall tear the surfaces apart at the critical temperaturehereinbefore named. The area of the head and shell which is subjected tothe heat is so localized that no general warping or creeping can takeplace, as has been found to be the case when attempts have been made tobraze the whole head in any one operation by heating the head in theshell in its entirety. In such case the equal cooling was foundimpossible and unequal cooling was the result, with a consequence thatwhen the temperature had receded to the critical point or brittleness ofthe brazing material the head and shell were torn apart and it was foundimpossible to make a tight package thereby.

We are aware that very thin sheets of metal tinned upon both sides, likecommon tin, have been soldered by an application of heat to their heads;but the operation of soldering does not require the heads to be heatedto anything like the temperature that brazing does or, in fact, to beheated at all, and soldering will take place although the surfaces arenot exactly contiguous to one another. The strain produced in solderingof this character is slight, if it practically exists at all; but in thecase of packages of heavy sheet metal such as we have described when thehigh heating necessary to brazing is used the strains are so great thatit has heretofore been found impractical, as already stated, tosuccessfully braze them together.

By the means hereinbefore described we have been enabled to brazepackages of sheet metal of an eighth of an inch or over in thickness. Infact, plates of almost any reasonable thickness, as boiler-plates, couldbe readilyand successfully brazed in the manner specified, and theessential features of this process consist in the holding and moving ofthe package in such manner between two independent adjustable sources ofheat that the requisite heat eifect is produced upon comparatively smalllocalized sections of the seam to be brazed, While at the same time itis subjected to the action of the fluxing material and the brazingmaterial by a successive or progressive action.

What we desire to claim is- 1. As a method of brazing packagesconstructed of heavy sheet iron or steel; first, temporarily uniting thehead portion and the body portion; second, arranging the package in suchmanner that the seam to be brazed, so formed of the head and the body,shall form a continually-progressive depression third, subjecting theunited head and body forming the seam each to aseparateindependentlycontrollable source of heat, and heating the samelocally to a high degree of temperature; fourth, feeding in fiuxing andbrazing material and fifth, slowly moving the package in such mannerthat the seam is subjected progressively to the sources of heat and thebrazing and fluxing material in the manner substantially as described.

2. The method of brazing an end into the cylindrical shell of a heavysheet iron or steel package consisting in fixing the end within thecylindrical shell in the position it is intended to occupy, revolvingsaid shell about its axis lying in an inclined position, applying asource of heat to a small area of said end at the periphery and at thelowest portion thereof, and simultaneously applying a source of heat toa small portion of the cylindrical shell adjacent to the heated portionof said end, and feeding fiuxing and brazing material into said packageat the heated portion thereof, substantially as described.

3. The method of brazing an end into the cylindrical shell of a heavysheet iron or steel package, consisting in forming said end with anupright flange around its periphery, fix- 1 lying in an inclinedposition,applying a source of heat to a small area of said flange andend at the lower portion thereof, and simultaneously applying a sourceof heat to a small portion of the cylindrical shell adjacent to theheated portion of said end and feeding fluxing and brazing material intosaid package at the heated portion thereof, substantially as described.

4:. The method of brazing an end into the cylindrical shell of a heavysheet iron or steel package, consisting in forming said end withanupright flange around its periphery, placing said end with said flangeoutward within the cylindrical shell, said flange lying against saidshell, turning the edge of said cylindrical shell over said flange so asto fix said end in place, revolving said shell about its axis 1ying inan inclined position, applying a source of heat to a small area of saidflange and end at the lower portion thereof, applying a source of heatto a small portion of the cylindrical shell adjacent to the heatedportion of said end and feeding fluxin g and brazing material into saidpackage at the heated portion thereof, substantially as described.

. In testimony whereof We sign this specification in the presence of twowitnesses.

JACOB o. DANZIGER. ARTHUR A. cowLns.

Witnesses:

MAY LOOKE, MAY E. Ko'rr.

